Bulletin of The Desert Legume Program of The Boyce Thompson Southwestern Arboretum and The University of Arizona

Volume 18, Number 2 August 2006 Legumes of Wallace Desert Gardens

Pamela Slate standing relationship between our Desert Gardens reviews and Botanic Coordinator organizations, one I see growing ever approves appropriate on-site Wallace Desert Gardens stronger year after year.” projects of mutual benefit. Wallace Desert Gardens is a Matthew B. Johnson non-profit foundation [(502(c)(3) In the mid-1980’s, the Program Manager and Curator under IRS rules] that was created in Wallace’s moved, complete with their Desert Legume Program 1993, well after much of the garden collection, from a Paradise was established. Its mission was Valley acre to a Scottsdale The virtues of desert legumes written by HB, as he was fondly subdivision where they purchased captured the attention of H.B. and known, to reflect the original intent of numerous acre-plus lots. At the time, Jocelyn M. Wallace when they first the foundation: HB had “no idea it would be bigger learned of the Desert Legume than a two-acre garden.” Although Program (DELEP) in 1989, about a Wallace Desert Gardens is a he “knew nothing of desert year after the program was founded collection of the world’s deserts when he moved to Arizona” in the at the University of Arizona. They plants located at an elevation of early 1980’s, they quickly became his understood the importance of some 2400 feet. Founded by passion. Today the garden legumes’ potential applications H.B. and Jocelyn M. Wallace in encompasses about eleven acres, worldwide as well as the position of the mid 1980’s, the gardens are having more than 16,000 plants DELEP as a committed champion. home to some twenty-five The resulting alliance between hundred species of which nearly Wallace Desert Gardens (WDG) and half are cacti. Some occupy the DELEP has been, in all aspects, Cactus Pavilion, a 6000-square- mutually beneficial. The Desert foot structure designed by H.B. Legume Program has received Wallace, primarily to protect financial support from Wallace tender species from desert Research Foundation and Mr. and temperatures that drop into the Mrs. Wallace personally. Wallace low twenties. Wallace Desert Desert Gardens became a trial/ Gardens serves its original evaluation garden for interesting and purpose of conserving and unusual species of accessioned protecting plants indigenous to legumes that are today one of its most deserts of the Americas. WDG valuable collections. Mark Bierner, also collects and manages plants Director of Boyce Thompson from other deserts of the world. Arboretum, DELEP’s parent It exemplifies biodiversity in organization, says the WDG legume cultivation and has an interest in collection “is certainly significant for rare and endangered desert botanical reasons. Just as flora. As a supporter of scientific importantly, it exemplifies the long- botanic research, Wallace H.B. Wallace 2 Aridus 18:2 2006

representing over 450 genera and teas and floribundas, in three flower. Their relatively large 2500 species. It is one of the most locations. and flowers and repeat flowering in extensive and extraordinary private In contrast to other botanic spring and fall in shades of pink, make collections found anywhere. Although gardens, WDG has a relatively short them especially appealing for urban HB passed away in August, 2005, he history. However, within that history, desert landscapes. left an enduring botanical legacy for its relationship with DELEP is longer Of interest are the DELEP the use and enjoyment of researchers, and more involved than with any other accession records themselves. For enthusiasts and students alike. botanic organization. The first DELEP example, seed for the Senna aphylla The Living Collection of seedlings were delivered to WDG in was collected in October, 1991 in La Plants (Pg. 7) provides an overview 1990, including berlandieri, Rioja Province, Argentina. of how the garden is defined. Plants A. constricta, A. eburnea, A. Peltophorum africanum seed came that accompanied the Wallace’s when millefolia,, A. notabilis, A rigidula, from Zimbabwe in July, 1990, they first moved to the property have A. spectabilis, Geoffroea Colutea istria from Israel in July, now reached specimen size, are decorticans, Havardia mexicana, 1989, Acacia cyperophylla from wondrous to all visitors and contribute Havardia pallens, Lucaena retusa, , in 1994 significantly to the collections. The Prosopis glandulosa var. and so on. As habitats worldwide are boojum “forest” is a unique mass glandulosa and Prosopis velutina. destroyed, “Botanic gardens play a planting of ten plants grown from seed Since then, legume seedlings have major role in testing new plants and collected under permit in the late been propagated for WDG each serve as storehouses for plant 1970’s. The plants arrived bare root year. diversity,” says WDG Board Member at WDG in the early 1990’s and The Desert Legume Program and botanist Kent Newland. today range in size from about seven supplied seed to several nurseries at The DELEP trial fields at the to twelve feet. All are thriving in soil, about the same time. Seed of other Yuma Mesa Agricultural Center, in climatic and horticultural conditions legumes planted at WDG from 1990 Yuma and the three sites at the U of that are obviously ideal for their to about 1995 can, in some cases, be A Campus Agricultural Center needs. In 2004, WDG acquired its traced through those nurseries back facilities, in Tucson are sites where Ephedra Collection from Stefanie to DELEP, particularly the more performance evaluations have been Ickert-Bond, Ph.D., who collected unusual ones from Australia, South conducted in recent years. All vary and studied the material in preparation America and Africa. Included in this widely in ecological factors – soils, for her dissertation at Arizona State category would be Acacia karroo, temperature, elevation, annual rainfall, University. Unsurpassed in the world, A. saligna, A. visco, Bolusanthus predation, horticultural factors, etc. it is the largest and most complete speciosus, Prosopis tamarugo, Due to a protected site and respresentation of New World Senna purpusii. As the mapping/ horticultural practices of four full-time Ephedra. database projects develop at WDG, staff, legumes at WDG receive The Yucca Collection has efforts will be made to trace DELEP constant nurturing, making them ideal 200 plants representing thirty seed through any of these nursery for evaluation as potential landscape accepted species. Twenty years of records. introductions as well as for legume growth have produced Yucca filifera, Not all horticulturally research. As Kent Newland explains, Y. faxoniana, Y. decipiens, Y. promising legume introductions “All botanic gardens are dependent valida, etc., in sizes upwards of ten originated with DELEP. For example, on collectors for clones of plants in feet, producing an extraordinary floral Mimosa martin-delcampoi was habitat and exist from without rather display for many spring months. originally collected by Ron Gass, than within; we are fortunate indeed Likewise, the Echinopsis collections owner of Mountain States Wholesale to have the interest of Matt Johnson attract neighbors, visitors and Nursery (Litchfield Park, AZ) and and the collections of the Desert professional photographers alike to Greg Starr, botanist and owner of Legume Program.” Beginning this fall, witness and capture the ephemeral, Starr Nursery (Tucson, AZ) near the legumes in the Wallace collection aromatic profusion of color. And no Miquihuana, Tamaulipas, Mexico. will also be evaluated on performance less popular are the Jocelyn M. WDG subsequently tested several using DELEP protocols, providing still Wallace Rose Gardens, a collection plants that have performed so well, another dimension of data to the of two hundred plants, mostly hybrid they captivate all who see them in program. Aridus 18:2 2006 3

to 18 ft. tall. The smooth reddish or orange bark contrasts with the foliage that consists of blue-green phyllodes resembling the leaves of some species of Eucalyptus. Yellow flowers in small heads are produced in winter and early spring. Coonavitra wattle appears to be reliably hardy to at least 15° F. It is native to areas of central and southern Australia. Under well-irrigated situations, this species can produce numerous root suckers. Amorpha fruticosa, false indigo, grows as 6-12 ft. tall. The plants are unarmed, with smooth, tan to gray bark. Leaves are once- pinnate and are winter-deciduous. Attractive, small, dark purple-blue flowers are produced in racemes at the ends of the stems in spring. This species is very cold tolerant. False indigo is widespread in the southwest United States and northern Mexico. Bolusanthus speciosus, wisteria, is a graceful, upright, unarmed tree growing 20-30 feet tall. The bark is cinnamon-brown, Acacia cyperophylla becoming deeply furrowed. The glossy green leaves are evergreen unless killed by frost. Beautiful and least 20° F. It is native to arid regions showy blue to mauve flowers are Among the many legumes of Australia. produced in long wisteria-like grown at the Wallace Desert Acacia galpinii, monkey thorn, is a racemes in spring. Cultivated tree Gardens, several species that are large, upright tree with a potential wisteria have survived overnight lows relatively new to Arizona horticulture mature height of 100 ft. though 50 ft. of 20° F without stem damage, have performed particularly well and is more common. Twigs are armed though the foliage is killed at are highlighted below. Several of with viciously sharp, paired, claw-like somewhat higher temperatures. This these were introduced by DELEP. thorns. The pale gray to tan bark tree is native to areas of southeastern Acacia cyperophylla, mineritchie or separates into strips. The foliage is Africa. red mulga, is an unarmed, multiple- gray-green and produces abundant Caesalpinia palmeri, palo piojo, is stemmed or small tree 10-15 ft. shade. Flowering has yet to be an unarmed shrub or small shrubby tall with an umbrella-shaped canopy. reported on trees in Arizona. Trees tree 10-20 ft. tall. The bark is pale A unique and attractive characteristic are damaged at about 22° F but gray with conspicuous white lenticels. is the smooth, reddish bark that peels recover quickly the following season. Small, dark green leaves are into numerous thin, curling strips along Monkey thorn is native to southern deciduous with drought or cold. the trunk and branches. The foliage Africa in parts of Botswana, Malawi, Yellow flowers with orange flecks on consists of narrow evergreen Mozambique, South Africa, Zambia, the upper petal are produced during phyllodes. Yellow flower heads and Zimbabwe. the summer months. This species is appear from winter into early summer. Acacia jennerae, coonavitra wattle, hardy to 20° F. It is native to Sonora This acacia appears to be hardy to at forms upright, unarmed shrubs or and Sinaloa, Mexico. 4 Aridus 18:2 2006

18° F. This species is native to parts of the Monte Desert of Argentina. Mimosa martin-delcampoi, bauhinia- mimosa, is an unarmed, upright shrub that grows 6-10 ft. tall. The bark is purplish, becoming gray on older stems. The leaves have rather large, leathery, kidney-shaped leaflets. Showy pink flower heads are produced in the summer. This plant is hardy to around 18° F. Native to southwestern Tamaulipas, Mexico, this species was introduced by Arizona nurserymen Greg Starr and Ron Gass. Prosopidastrum globosum, caballo de diablo, is a spreading, spiny shrub growing 6-10 ft. tall with green, sharp-tipped twigs. The leaves are small and deciduous with cold or drought. White flowers are produced in rounded heads in summer and autumn. This species is very cold hardy – perhaps to below 0° F. It is native to parts of central Argentina. Prosopis reptans var. cinerascens, dwarf screwbean, is a low subshrub to 1 or 2 feet tall, spreading by root- Acacia galpinii sprouts. The stems have paired, white dense, upright growth habit. Plants spines. Small, blue-green leaves are Caesalpinia paraguariensis, grow during the cooler months and cold deciduous. Bright yellow flower guayacán, is a spectacular, unarmed, become dormant and partially heads in summer are followed by spreading tree growing 25-50 ft. tall. deciduous in summer. Flowers are coiled pods that turn bright yellow The bark is smooth and mottled with bright yellow and -like with and remain on the plants for months. green, gray, tan, and beige, exfoliating orange coloration on the banner petal. Dwarf screwbean is hardy to at least in plates or strips, and resembles the Flowering is in February and March. 15° F. The plants are native to bark of some species of eucalyptus. This plant gets its common name from southern Texas and eastern Mexico. Newly emerging leaves are rust- the inflated seed pods. Bladder senna The tendency to spread by root- colored, changing to dark green. The is reliably hardy to 15° F. It is native sprouts can become a problem in plants are deciduous with freezing to parts of Israel, Jordan, and Syria. well-irrigated situations. temperatures. Small yellow flowers Mimosa ephedroides, prendador, is Senna aphylla, leafless senna or are scattered through the canopy a shrub that resembles species of pichanilla, forms unarmed spreading during the summer. It is hardy to Ephedra, Mormon tea, as the shrubs to 6 ft. tall and 8-10 ft. across. about 18° F. Guayacán is native to specific epithet suggests. This mimosa The bright green stems are leafless forest habitats in the Gran Chaco is unarmed and grows as an upright after the seedling stage. Older stems Region of northern Argentina, shrub to 6 ft. tall with green stems and sometimes turn orange or brown. southern Bolivia, western Paraguay, small, deciduous leaves. White to pale Showy masses of bright yellow and southwest Brazil. pink flowers in rounded heads are flowers are periodically produced in Colutea istria, bladder senna, is an produced in summer. It is hardy to unarmed shrub 6-8 ft. tall with a (Continued on page 5) Aridus 18:2 2006 5

Staff and Volunteers in Action

DELEP’s Tucson Fields: 18 before our first planting. We were 7047 or email me at Years of Volunteer Effort quick to plant these when we ac- [email protected] to learn quired the space. Lupins have been more about DELEP’s volunteer pro- grown in other areas of the borders gram. DELEP’s earliest field and their seeds were mostly direct plantings, from 1989 through 1994, seeded into the field. were made with the goal of learning During the past seventeen many things about known and little- (Continued from page 4) years, we’ve assembled a great deal response to moisture from spring known desert legumes. Our realistic of horticultural information from those through fall. Established plants have expectation was that some of these plantings as well as substantially in- survived 15° F without damage. specimens and species would likely creasing seed quantities. Leafless senna is native to central and not survive. DELEP fields lie in an Efficient application of irriga- northwest Argentina. area of extreme cold air drainage, and tion water is a key to plant success in Senna purpusii, Baja California are reported to be one of the coldest both landscape and research situa- senna, is an unarmed shrub 3-4 ft. tall areas of the Tucson valley during win- tions. It is also an important means with gray bark. The drought ter months. As such, they are in a for water conservation while simulta- deciduous leaves have bluish green great location to evaluate species for neously reducing weed problems. leaflets, often with red-purple frost-hardiness, or tenderness. Most During June of this year, Adam Ryan margins. Showy yellow flowers specimens planted there survived, and I completed the installation of a appear in winter and spring. This while some have struggled (and have drip irrigation system in borders three species is hardy to about 24° F. been mostly unremarkable in perfor- and four. The challenge of burying Native to the Pacific slope of the mance). Others did not survive be- irrigation tubing around the mature north central Baja California yond their first or second winter. (See plant specimens was a happy chal- peninsula, Mexico. ARIDUS, Volume 16, number 3 lenge (even at 100°F), as we pon- Other legume introductions continue [November 2004]). Still, the primary dered the more positive effect that to be planted at the Wallace Desert goal of those plantings was one of would be created for those plants. Gardens for evaluation and many of increasing our seed supplies for fur- Nearly 400 drip emitters were care- these are showing promise as ther research and exchange, while fully placed around the plants in those excellent landscape plants. ultimately creating an aesthetically two borders. We did this in DELEP’s pleasing park-like atmosphere. Hun- oldest border two years ago. Plants For further information on the dreds of woody plants and several there and at our West Campus field Wallace Desert Gardens, please lupin species are included. Some have grown well under drip irrigation, contact: plants that did not survive here were with the additional benefit of signifi- Pamela Slate, Botanic Coordinator re-planted successfully in our Yuma, cantly reduced weed problems. Wallace Desert Gardens Arizona fields. Thanks to the UA Campus Agricul- 30600 North Pima Road, #57 Both, trees and shrubs were tural Center staff for their work, in- Scottsdale, AZ 85262 planted in three consecutive but sepa- stalling the hard pipe and new valves. phone: (480) 488-8003 rate “borders”. Matt organized the Fall 2006 volunteer session email: [email protected] field layout considering factors such dates are scheduled for September as the separation of lesser-known 13th, October 11th, November 8th, species that might cross-pollinate or and December 13th. DELEP’s Advi- become weedy. Specimens were sory Board will meet again on Sep- grown by volunteers during the year tember 15th. Please call 520-318- 6 Aridus 18:2 2006

Delep Personnel

Wallace Desert Gardens Mark Bierner, Ph.D. List of Accessions from the Director Desert Legume Program Matthew B. Johnson Botanical Specialist

Caesalpinioideae Acacia oswaldii Ken Coppola Bauhinia lunarioides Acacia pachyacra Horticulturist Caesalpinia paraguariensis Acacia patagiata Peltophorum africanum Acacia permixta Margaret Norem, Ph.D. africana Acacia quadrimarginea Editor Aridus Senna aphylla Acacia quornensis Bruce Klewer Senna pleurocarpa var. Acacia rivalis Administrative Assistant pleurocarpa Acacia roemeriana Acacia schottii Volunteer Coordinators Acacia victoriae Glenn Branham Acacia acuminata subsp. burkittii Albizia sinaloensis Pamela Honaker Acacia adsurgens Mimosa ephedroides Jamie Wahl Acacia angustissima var. Mimosa farinosa Yuma Fields angustissima Painteria elastichophylla Acacia aroma Prosopidastrum globosum Dan Sims Acacia brachystachya Prosopis nigra Greenhouses Acacia cheelii Prosopis reptans var. cinerascens Advisory Board Acacia crassifolia Acacia cyperophylla Papilionoideae Rita Jo Anthony Acacia furcatispina Amorpha fruticosa Acacia galpinii Bolusanthus speciosus Elizabeth Davison Acacia gerrardii subsp. negevensis Brongniartia minutifolia David Ellis, Ph.D. Acacia grandicornuta Colutea istria Acacia haematoxylon Coursetia glandulosa Stefanie Greene, Ph.D. Acacia harveyi Eysenhardtia orthocarpa Acacia jennerae Eysenhardtia texana Leslie Gunatilaka, Ph. D. Acacia kempeana Psorothamnus spinosus Ryan Huxtable, Ph.D. Acacia microcarpa Retama raetam Acacia millefolia Schotia afra var. afra Ken Morrow Acacia nebrownii Schotia afra var. angustifolia Acacia neovernicosa Tephrosia leiocarpa Suzanne Nelson, Ph.D. Acacia occidentalis Kathleen C. Rice

Ursula Schuch, Ph. D.

Barbara Timmerman, Ph.D. Aridus 18:2 2006 7

T he L iving C ollection of Plants PLANT TYPE DESCRIPTION EXAM PLE TAXA Aloe ram osissima, Ferocactus pilosus Inclu de the oldest, m ost (c lu m p ), Echinocactus platyacanthus, Specimen m atu re p lan ts in th e collection Euphorbia resinifera, Neobuxbaum ia Plants from any source. They m ay be s c o p a ria , M y rtillo c a c tu s c o c h a l, C h o ris ia considered irreplaceable. hybrid, Yucca collection. In clu d e all p lan ts in th e garden that are accessioned Ephedra C o lle c tio n , a ll p la n ts fro m prior to placem ent at W DG . Desert Legum e Program (DELEP), The

T hey are from the D esert Huntington Botanical Garden (HBG), Plants Legum e Program , other Desert Botanical Garden (DBG) and w ith D a ta botanical gardens and/or are plants w hose seed or tissue is of know n of know n provenance. These provenance; may include several p la n ts m a y in trin sica lly have nursery - g ro w n sp ecies, e.g ., Agave O p u n tia s te n o p e ta la , S a lv ia s im ilis , S . Include plants not com m only d o o rii, P o ly g a la m itrifo lia . U rg in e a Unusual found elsew here in cultivation. m aritima, Yucca endlichiana, Fouquieria Plants The seed or plant m ay, but not colum naris, Uncarina spp. necessarily, be from Cyphostem m a juttae, Boophone Include hybrids and selections Dioon edule subsp. edule, Fouquieria w h o se v a lu e is in th eir d ig u e tii, S a b a l m in o r, Ip o m o e a lo n g ifo lia ,

horticultural, cultural and Tecom a garocha, M imosa m artin- T ria l aesthetic characteristics. delcam poi, Schinopsis quebracho- S e le c tio n s They m ay be view ed as c o lo ra d o , M a ire a n a s e d ifo lia , M e lia n th u s experim ental and/or trials for major, DELEP Accessions Larrea tridentata, Carnegiea gigantea, Include plants already on the Canotia holacantha, Ephedra aspera, Native property prior to form ation of Yucca baccata, Ferocactus w islizeni, F. Plants WDG. cylindraceus, Fouquieria splendens, Opuntia spp, Prosopis s p p ., Parkinsonia spp O ln e y a te s o ta Include H ybrid T ea, Floribunda, Grandiflora, Rose Climbers and Ramblers, ‘P e a c e ’, ’C la s s A c t’, ’Q u e e n E liz a b e th ’, C o llectio n English and M iniature ’W h ite D a w n ’, ’P rid e ‘n J o y ’ selectio n s, a ll 1 5 0 -2 0 0 Landscape Include all other plants of

Plants nursery stock.

Tree Logo Opportunities for Participation Here

DELEP’s bulletin Aridus, is published Financial support for DELEP comes Dedicated volunteer work is an integral three times annually to stimulate interest from contracts, grants and contributions component of DELEP. Our volunteers in desert legumes, to inform our readers from private industries, government come from many backgrounds and work of DELEP’s activities, and to encourage agencies and individuals. on a variety of projects including wild support for DELEP’s programs. Manu- seed collecting, seed processing, organi- scripts related to legumes are welcome To Contribute: Send a check, payable zation of special events, and office work. and should be mailed to the editor for to U of A Foundation/ DELEP, or call review. Subscriptions are complimen- the DELEP Office concerning a pledge, tary and are available by contacting the a restricted gift, or estate planning. To Volunteer: Or just to explore the DELEP office. Aridus is published by The Desert Legume Program possibilities, telephone our office (520) 318- The University of Arizona on behalf of 2120 E. Allen Road 7047) or drop us a note or email: The Desert Legume Program. Tucson, Arizona 85719 [email protected]. 8 Aridus 18:2 2006

Mimosa martin-delcompoi

The University of Arizona Desert Legume Program NON-PROFIT 2120 East Allen Road ORGANIZATION U.S. POSTAGE PAID Tucson, Arizona, 85719 PERMIT NO. 190 U.S.A. TUCSON, ARIZONA

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